EoIP

Document revision:

1.4 (Fri Nov 04 20:53:13 GMT 2005)

Applies to:

V2.9

General Information

Summary

Ethernet over IP (EoIP) Tunneling is a MikroTik RouterOS protocol that creates an Ethernet tunnel between two routers on top of an IP connection. The EoIP interface appears as an Ethernet interface. When the bridging function of the router is enabled, all Ethernet traffic (all Ethernet protocols) will be bridged just as if there where a physical Ethernet interface and cable between the two routers (with bridging enabled). This protocol makes multiple network schemes possible.

Network setups with EoIP interfaces:

Possibility to bridge LANs over the Internet

Possibility to bridge LANs over encrypted tunnels

Possibility to bridge LANs over 802.11b 'ad-hoc' wireless networks

Quick Setup Guide

To make an EoIP tunnel between 2 routers which have IP addresses 10.5.8.1 and 10.1.0.1:

On router with IP address 10.5.8.1, add an EoIP interface and set its MAC address:

Related Documents

Description

An EoIP interface should be configured on two routers that have the possibility for an IP level connection. The EoIP tunnel may run over an IPIP tunnel, a PPTP 128bit encrypted tunnel, a PPPoE connection, or any connection that transports IP.

Specific Properties:

Each EoIP tunnel interface can connect with one remote router which has a corresponding interface configured with the same 'Tunnel ID'.

The EoIP interface appears as an Ethernet interface under the interface list.

This interface supports all features of an Ethernet interface. IP addresses and other tunnels may be run over the interface.

The EoIP protocol encapsulates Ethernet frames in GRE (IP protocol number 47) packets (just like PPTP) and sends them to the remote side of the EoIP tunnel.

Maximal count of EoIP tunnels is 65536.

Notes

WDS significantly faster than EoIP (up to 10-20% on RouterBOARD 500 systems), so it is recommended to use WDS whenever possible.

remote-address - the IP address of the other side of the EoIP tunnel - must be a MikroTik router

tunnel-id (integer) - a unique tunnel identifier

Notes

tunnel-id is method of identifying tunnel. There should not be tunnels with the same tunnel-id on the same router. tunnel-id on both participant routers must be equal.

mtu should be set to 1500 to eliminate packet refragmentation inside the tunnel (that allows transparent bridging of Ethernet-like networks, so that it would be possible to transport full-sized Ethernet frame over the tunnel).

When bridging EoIP tunnels, it is highly recommended to set unique MAC addresses for each tunnel for the bridge algorithms to work correctly. For EoIP interfaces you can use MAC addresses that are in the range from 00-00-5E-80-00-00 to 00-00-5E-FF-FF-FF, which IANA has reserved for such cases. Alternatively, you can set the second bit of the first byte to mark the address as locally administered address, assigned by network administrator, and use any MAC address, you just need to ensure they are unique between the hosts connected to one bridge.

Example

To add and enable an EoIP tunnel named to_mt2 to the 10.5.8.1 router, specifying tunnel-id of 1:

EoIP Application Example

Description

Let us assume we want to bridge two networks: 'Office LAN' and 'Remote LAN'. The networks are connected to an IP network through the routers [Our_GW] and [Remote]. The IP network can be a private intranet or the Internet. Both routers can communicate with each other through the IP network.

Example

Our goal is to create a secure channel between the routers and bridge both networks through it. The network setup diagram is as follows: